This invention relates to a current overload fuse, and in particular to a plug-in fuse formed on a substrate.
A conventional plug-in fuse is disclosed in U.S. Pat. No. 3,909,767. The plug-in fuse is preferably disposed in a housing. Also, a substrate-type plug-in fuse is disclosed in Japanese Patent (A) 53-109,156. In the Japanese patent application, a plurality of circuits as fuses are printed on front and rear surfaces of a substrate made of thermosetting property resin such as phenol resin. The circuits are plated with tin of a predetermined thickness in order to enhance the conductivity. The circuits are to be inserted in socket openings and received by pressure spring clips in the openings. When the substrate is inserted in the socket openings, the circuits are scratched by the pressure spring clips, and the plating may be peeled from the substrate. As a result, failure in the conductivity occurs.
In the market there is a need of plug-in fuses which can be directly inserted in pressure terminals.
The object of the present invention is therefore to provide a substrate-type plug-in fuse which can be directly plugged in slots of the pressure terminals and absorb force caused on the terminals of the fuse by the pressure terminals in order to maintain good conductivity.